Home > Publications database > Anwendung und Optimierung von Coat-Mix-Werkstoffen als Kokillenmaterial für den Metallguß |
Book/Report | FZJ-2018-06964 |
; ;
1994
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
Jülich
Please use a persistent id in citations: http://hdl.handle.net/2128/20270
Report No.: Juel-2959
Abstract: Coat-Mix(CM)-materials are ceramic materials consisting of filler and binder components, which are produced in a special mixing process. They have an interconnected, open porosity and an exellent thermal shock resistance. Further the thermal, mechanical and chemical properties of these materials can be achieved by variation the filler and binder composition. An important application for CM is the use as a permanent die material. In this present publication the effects of the mold composition and process parameters on production- (green body strength, shrinkage, real density) and application properties (bending strength, air permeability, thermal conductivity, open porosity) have been investigated. These different CM compositions were used for casting experiments for measuring thecooling rate of the permanent die material and the casting properties (fluidity, die filling capability, hot tearing behaviour) of AISi- and PbSb/Ca-alloys. Electrographitewas used as a filler material. The same casting experiments were duplicated with a grey iron mold. The oxidation behaviour of the CM-material has been investigated by means of thermal gravimetry in a flowing dry air medium at a temperature range of 400°C to 600°C. Hereby the reaction rate of the oxidation was measured andcalculated by following the temporal burn off. Following results were achieved: the variation of the process parameters while producing CM-materials allows to adjust the casting properties of the CM mold in distinct ranges. The cooling properties of the die made of grey iron is higher than the cooling properties of the CM die. While using a CM-material with higher binder content (35%) the cooling properties and the die filling capability of AlSi-alloys are similar to the grey iron die. The die filling capability is less in CM-material in comparison to grey iron while using an PbSb-alloy. The fluidity of AlSi-alloys and PbSb-alloys is above a certain temperature in CM mold higher than in a grey iron die. The fluidity of the PbCa-alloy is better than in a grey iron die at all invatigated die temperatures. The investigation about the hot tearing behaviour has shown a reduced tendency to hot tearing in CM-material than in grey iron material for the AISi- and PbSb-alloys. The examination of the oxidation behaviour reveals that the oxidative burn off while using CM with electrographite filler material has no severe influence on the die life below 400°C die temperature.
The record appears in these collections: |